Leaking out barrel Icon Z

My friend has an icon z which was leaking near his Asa, and I told him I would Teflon it up and it would be fine. Later that day it started leaking out his barrel bad. When we got home I took it all apart for him and really couldn't tell what the problem was. Nothing seemed out of place. He didn't have the manual so I couldn't look at the schematics. I know leaking out the barrel is common and caused by few reasons. Any ideas? Thanks

My son has an Icon X that we use as a loaner gun now. He only used it like 3 times before he boght his 98. The other day, it started leaking air around the cocking knob. When we got home, I put a tank back on it & it started gushing air out down the barrel & around the body. I took it apart & replaced all 3 of the o-rings that I could find (the gun came w/ 3). Put the tank back on & still have the same problem. WTH?

I will have to take it back apart & double check it. I am considering picking up an Icon Z tomorrow for $15. Supposedly it works fine w/ the exception of a broken trigger. Worthwhile purchase? May pirate the trigger off the X if it fits.